2142. What character can be added to both of these characters to give other characters? 安_ -> _全

安  AN, yasu(i) - peace, cheap

全  ZEN, matta(ku) - all

Add 木:安+木 木+全  

木  MOKU, BOKU, ki - tree

案  AN - plan, proposal

栓  SEN - stopper, cork, plug